When Roshan is talking with Gibson in the bar, first Roshan is on the right and Gibson on the left. In the next scenes they are shown the other way around.
When Neil meets with an accident the phone he is carrying has a silver display in front but when the phone is shown fallen, it is fully black.
When Sam is playing chess at the University with the Asian guy, the board is shown from the top; there is one chess cube free between the two kings. In the next scene the kings are shown next to each other. That is not possible because both of them would be in check. Plus, Sam is making checkmate by taking the white king with the black king. That is against the rules of chess.
Omar tells Maya that he has not been around, because their college experience will soon be over, and he has been packing. Then we see the reports of 9/11. But 9/11 happened at the beginning of a college semester, not near the end of one.
Neil Mukesh gets admission into New York State University. There is no university with that name - the state university in New York is called as State University of New York (SUNY)
When the Aerial view of New York is shown during the opening credits, a shadow of the helicopter used to shoot the scene is visible on the external glass surface of some buildings.
The co-ordinates shown on the camera of the interrogation room are 40 45 21.79 N
73 59 14.26 E, which is in Kyrgyzstan - not in New York. New York is at 73 59 14.26 West, not East.
The "Brooklyn Market" Samir goes to get the brown bread is the Italian Market in Philadelphia, likely somewhere along Passyunk Avenue. A sign for the Pennsylvania Lottery can be see on a storefront in the background.